Toxicology Commons^™

Characterizing The Effects Of Antiandrogens And Senolytics To Enhance The Therapeutic Response To Castration-Resistant Prostate Cancer, Justin M. Silverman

Theses and Dissertations

Prostate cancer is the most frequently diagnosed cancer in males and the second most common cause of cancer deaths. Androgen deprivation therapy, whether through surgical or chemical castration, is the mainstay for treatment of advanced prostate cancer; however, despite an initial response, most patients eventually develop a progressive PSA rise, and castration- sensitive prostate cancer gives rise to castration-resistant prostate cancer. The standard of care therapy includes the antiandrogens such as enzalutamide and abiraterone acetate as well as the microtubule poison, docetaxel, and various immunotherapies; however, while prostate cancer research is progressing, there continues to be a compelling need for …

Telomeres: A Tool To Assess The Impacts Of Mining Contaminants On Riparian Songbirds, Lillian Krach, Bridger Creel, Megan Fylling, Zac Cheviron, Creagh Breuner

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Mining has left massive environmental and physical scars across the landscape. Aquatic and riparian landscapes in particular have been significantly impacted by traditional mining practices. Waste products left over from hard-rock mining leech heavy metals onto the landscape and these metals spread from headwater streams to major waterways (Lottermoser 2010). Heavy metals have been shown to cause physiological stress and challenges to organisms depending on the metal and the concentration (Baos et al. 2019, Boyd & Rajakaruna 2013). While some mining-impaired areas have undergone restoration efforts, is it enough? Typical restoration methods replace the contaminated floodplain, but not the riverbed …

Trends In Cyanotoxin Production Potential In China Lake: An Edna Analysis Of Microcystis And Dolichospermum And The Environmental Drivers Of Cyanotoxin Production, Gennifer M. Rubin

Honors Theses

Episodes of cyano-harmful algal blooms (cyano-HABs) are hypothesized to be exacerbated by the effects of climate change. However, the dynamics of the interactions between elements of climate change and toxigenic cyanobacteria proliferation are not well defined. China Lake is the drinking water source for 7 municipalities in the Kennebec County and is one of many lakes in central Maine that has been subjected to high levels of cyano-HABs and microcystin toxin contamination in recent years. Monitoring the toxicity of these blooms in relation to various aspects of climate change may lead to identification of the major drivers of microcystin production …

Examining The Oxidative Stress Effects In Rats Exposed To 2-Aminoanthracene In Utero And High Fat Diet Three Months After, Brianna A. Lanoix

Honors College Theses

Polycyclic aromatic hydrocarbons are organic compounds that are created synthetically or found in partially burned oil, gasoline, and coal. 2-aminoanthracene (2AA) is a common example of a PAH and can affect lipid and carbohydrate metabolism and resulting in inflammatory problems and oxidative stress. The objective of the research project is to investigate oxidative stress in relation to diabetes in rats exposed to 2AA in utero and a high fat diet later in life. Pregnant dams were separated into treatment groups based on their dosages of 2AA; 0 mg/kg (control), 50 mg/kg (low), 100 mg/kg (high). During the gestation -postpartum period, …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Bioaccumulation Of Polychlorinated Biphenyl Compounds And Mercury In A Mining Impacted Aquatic Ecosystem, Michelle Bollini

Dissertations, Master's Theses and Master's Reports

The Keweenaw area continues to be influenced by the century of copper mining that ended nearly 50 years ago. This project is focused on Torch Lake, an aquatic ecosystem that has been heavily impacted by mining waste disposal. The watershed has been impaired by mine discharge and tailings, smelter and smokestack plumes, and poor waste disposal practices. The lake is listed as a Great Lakes Area of Concern with beneficial use impairments of restrictions on fish consumption and a degraded benthic community. Polychlorinated biphenyl compounds (PCBs) and methylmercury (MeHg) are persistent, bioaccumulative, and toxic substances (PBTs). These contaminants pose threats …

Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott

Cal Poly Humboldt theses and projects

Harmful algal blooms (HABs) result from outbreaks of any of several different species of toxin-producing phytoplankton and that can have major detrimental effects on marine ecosystems and pose severe health and economic threats to human communities. Of particular concern along the United States West Coast are HABs of pennate diatom genus Pseudo-nitzschia that produce the potent neurotoxin domoic acid (DA). The coastal ocean between Cape Mendocino, CA, and Cape Blanco, OR is a hotspot for Pseudo-nitzschia spp. HABs. Such blooms impact coastal fisheries and pose a potential threat to aquaculture operations in Humboldt Bay, California’s second largest estuary and largest …

Halogen Bonding Interactions Of Haloaromatic Endocrine Disruptors And The Potential For Inhibition Of Iodothyronine Deiodinases, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Halogen bonding (XB) is a potential mechanism for the inhibition of the thyroid-activating/deactivating iodothyronine deiodinase family of selenoproteins through interactions with halogenated endocrine disrupting compounds (EDCs). Trends in XB interactions were examined using density functional theory for a series of polyhalogenated dibenzo-1,4-dioxins, biphenyls, and other EDCs with methylselenolate, a simple model of the Dio active site selenocysteine. The strengths of the interactions depend upon the halogen (Br>Cl), the degree of substitution, and the position of the acceptor. In terms of donor-acceptor energies, interactions at the meta position are often the strongest, suggesting a link to the topology of THs, …

Co-Occurrence Of Marine And Freshwater Phycotoxins In Oysters, And Analysis Of Possible Predictors For Management, Sarah K. D. Pease, Todd A. Egerton, Kimberly S. Reece, Marta P. Sanderson, Michelle D. Onofrio, Evan Yeargan, Adam Wood, Amanda Roach, I-Shuo Wade Huang, Gail P. Scott, Allen R. Place, Amy M. Hayes, Juliette L. Smith

Biological Sciences Faculty Publications

Oysters (Crassostrea virginica) were screened for 12 phycotoxins over two years in nearshore waters to collect baseline phycotoxin data and to determine prevalence of phycotoxin co-occurrence in the commercially and ecologically-relevant species. Trace to low concentrations of azaspiracid-1 and -2 (AZA1, AZA2), domoic acid (DA), okadaic acid (OA), and dinophysistoxin-1 (DTX1) were detected, orders of magnitude below seafood safety action levels. Microcystins (MCs), MC-RR and MC-YR, were also found in oysters (maximum: 7.12 μg MC-RR/kg shellfish meat wet weight), warranting consideration of developing action levels for freshwater phycotoxins in marine shellfish. Oysters contained phycotoxins that impair shellfish health: karlotoxin1-1 and …

Promoting Healthier Treatment Outcomes In Obese Cancer Patients Taking High Dose Methotrexate, Carly Dell'ova

Walden Dissertations and Doctoral Studies

Cancer and obesity rates continue to rise, creating enormous public heath burdens to the individual and at the national and global levels, reducing quality of life, and increasing spending. Moreover, the relationships between cancer and obesity are not well understood. A commonly used chemotherapy for several types of cancer is high dose methotrexate (HDMTX). Along with chemotherapy, especially at high doses, comes toxicity to specific organs and the entire body. However, limited research has been conducted on obese cancer patients as they are often excluded from clinical studies. Practitioners need to better understand how to dose these patients to provide …

Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry Quantitation Of O-Cresol In Hydrolyzed Human Urine To Assess Toluene Exposure, Eric Langlois, Sébastien Gagné

Études primaires

Rationale

Toluene is a volatile organic compound used in domestic and industrial applications. The main routes of workplace exposure to toluene are inhalation and dermal contact. As toluene exposure can cause severe nervous system damage, its quantification is crucial to prevent occupational illness. Toluene is metabolized mainly as hippuric acid, S-benzylmercapturic acid and epoxides. These are rapidly converted to o-/p-cresol, which is then excreted in the urine as conjugated glucuronides and sulfates. o-Cresol and its conjugates can be chemically hydrolyzed to form free o-cresol, which can then serve as a urinary biomarker of toluene exposure. Current …

Gut-Lung Axis Of The Microbiome Alterations After Ultrafine Particles And Ozone Inhalation, Md Habibul Hasan Mazumder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Air pollution poses a significant threat to public health. It is a mixture of particulate matter, gaseous substances, and other secondary substances. Despite epidemiological research indicating the interactive effects of various components of air pollution, existing studies and regulatory limits often focus on single-exposure scenarios. The emerging understanding of the microbiome’s role in regulating immune response, metabolism, and pathophysiology of various diseases points towards interactions between environmental exposures and microbial dysbiosis. In this dissertation, mice were exposed to relevant deposited doses of carbon black (CB) and ozone (O3), and lung inflammation as well as the lung-gut axis of the microbiome …

Quantification Of Phosphatidylethanol In Whole Blood And Dried Blood Spots By Lc-Ms/Ms, Elizabeth Yulianto

Student Theses

Phosphatidylethanol (PEth) is an alcohol biomarker that provides a longer window of detection than direct alcohol measurement or other common alcohol metabolites, like ethyl glucuronide. PEth has become useful in assessing drinking history, such as for alcohol-withdrawal treatment, organ transplant settings or prenatal alcohol exposure determination. A method was developed and validated to quantify PEth 16:0/18:1 and 16:0/18:2 in whole blood and dried blood spots (DBS) by liquid chromatography tandem mass spectrometry (LC-MS/MS). The whole blood method was applied to 149 samples from pregnant women, elucidating possible prenatal alcohol exposure. Fifty μL whole blood and 12.7 mm whole punches from …

Inhibition Of Rad18 By Arsenic, Lindsay B. Volk

Biomedical Sciences ETDs

Arsenite exposure leads to the retention of UV-induced DNA damage, thus burdening translesion synthesis (TLS). Rad18 is an essential factor in initiating TLS through PCNA monoubiquitination and is implicated in homologous recombination. It contains two functionally and structurally distinct zinc fingers that are potential targets for arsenite binding. Results from this study reveal arsenite binding to both zinc fingers of Rad18 and a corresponding loss of domain function. Importantly, arsenite inhibited Rad18 RING-dependent PCNA monoubiquitination and polymerase eta recruitment to DNA damage. Further analysis demonstrated multiple effects of arsenite, including the reduction in the nuclear localization and UV-induced chromatin recruitment …

Hepatocyte-Hepatic Stellate Cell Axis In Potentiation Of Alcohol And Hiv-Induced Liver Injury, Moses O. New-Aaron

Theses & Dissertations

Human Immunodeficiency Virus (HIV) remains a global threat, with approximately 38.4 million active infections and 33 million HIV-related deaths since the first case. While many may be tempted to think of HIV as a relic of the past, emerging data suggests otherwise. By the end of 2021, approximately 1.5 million HIV incidences and 650 000 mortalities were reported globally. The etiologies of HIV-related mortality are numerous. Liver disease is one of the leading etiologies of HIV-related mortality, especially in recent times of antiretroviral therapy (ART)-induced longevity among people living with HIV (PLWH). While co-infections with hepatotropic viruses notoriously contribute to …

Étude Visant À Mieux Guider L’Évaluation Des Risques Des Travailleurs Exposés Aux Nanoparticules (Np) : Existe-T-Il Différentes Propriétés Inflammatoires Des Np Liées Au Sexe?, Marion Vanharen, Abdelaziz Saafane, Alexanne Léveillé, Thomas Mahbeer, Denis Girard

Rapports de recherche scientifique

Les nanotechnologies offrent un important potentiel d’exploitation dans des secteurs industriels variés, pour lequel les bénéfices financiers ne sont pas négligeables. À l’instar des provinces canadiennes et de nombreux pays industrialisés, le Québec voit un nombre grandissant de compagnies produisant des nanomatériaux et des nanoparticules (NP) se développer, sans oublier celles qui introduisent de plus en plus de NP dans leurs produits. Le nombre de travailleurs québécois œuvrant dans la fabrication et dans la synthèse des NP augmentera dans les années à venir. De plus, le nombre de travailleurs appelés à manipuler et à transformer des NP dans les domaines …

Effects Of Microcystin-Lr On Channel Catfish (Ictalurus Punctatus) Susceptibility To Microbial Pathogens (Aeromonas Hydrophila And Edwardsiella Piscicida), Alison Marchant

Theses and Dissertations

Microcystin-LR is a hepatotoxin produced by cyanobacteria. Aeromonas hydrophila and Edwardsiella piscicida infections are leading causes of losses in market-sized channel catfish (Ictalurus punctatus). These older fish should have natural immunity in place and a predisposing factor is likely a prerequisite for these disease outbreaks. While microcystin-LR rarely causes mortality in warm-water aquaculture, we believe it may be a predisposing factor that leads to bacterial disease outbreaks during the summer months due to its ability to damage the liver. Our study investigated microcystin-LR’s effects on channel catfish susceptibility to these pathogens. We found that a sublethal dose of microcystin-LR induced …

Quantifying The Toxicological Effects Of The Organic Uv Filters Avobenzone And Homosalate On Acropora Cervicornis, Samantha F. Buckley

All HCAS Student Capstones, Theses, and Dissertations

Reports of the environmental effects of organic UV filters such as oxybenzone have led to the marketing of “reef-safe” sunscreen ingredients, including avobenzone and homosalate. Avobenzone provides broad-spectrum UV protection which blocks higher wavelength UV rays, the leading cause of aging and skin cancer. However, as polycyclic aromatic hydrocarbons (PAHs), organic UV filters have similar structures to crude oil and estrogens, some of which have been labeled endocrine disrupters. Common in personal care products, UV filters enter marine ecosystems via wastewater effluent and swimmers. Significant stress and mortality have been observed in juvenile and some adult scleractinian corals after exposure …

Effects Of Titanium Dioxide Nanoparticle Injections On Tissue Function And Morphology In Goldfish (Carassius Auratus), Bryan Joel Patterson

Graduate Theses

Fish gills are sensitive to a variety of environmental factors because they regulate the exchange of oxygen and ions between the fish and the external environment. This study examined the effects of polyacrylic acid (PAA) coated titanium dioxide nanoparticle injections (TiO₂ NPs) on goldfish (Carassius auratus) over 14 days. Following the experimental period, we examined gill histological samples and looked for signs of an inflammatory response through blood glucose levels and relevant gene expression. TiO₂ injected fish developed a more robust ILCM (interlamellar cell mass) compared to the non-injected controls, which remained elevated over 14 days post injection. …

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …